My favorite games of 2012 (You may also include games from previous years):
3DS: 5.) New Super Mario Bros. 2 4.) The Legend of Zelda Ocarina of Time 3D 3.) Crashmo 2.) Paper Mario Sticker Star 1.) Super Mario 3D Land
Wii: 5.) Super Smash Bros. Brawl 4.) Rayman Origins 3.) Super Mario Galaxy 2.) Legend of Zelda: Skyward Sword 1.) Super Mario Galaxy 2
I don't own a Wii U yet, but I've played most the Wii U games at a local mall and at Best Buy. Judging by what I've played:
Wii U: 3.) Nintendo Land 2.) New Super Mario Bros. U 1.) Rayman LegendsWhat I played were demos/timed trials. So these opinions are not official until I own and played through all of these games. This is not my final opinion on these Wii U games. Do not put any comments below on me judging a game before it's released.
Overall: Super Mario Galaxy 2! Best Wii game of all time. If you're only gonna buy one Wii game, EVER, then buy this and don't hesistate.
Now share your best gaming experiences of whatever year you're in.EDIT: Turns out I got a Wii U for Christmas! So here are my favorite Wii U games.
5.) Tekken Tag Tournament 2 4.) Skylanders Giants 3.) Sonic & All-Stars Racing Trasformed 2.) Nintendo Land 1.) New Super Mario Bros. U
Overall: STILL Super Mario Galaxy 2
But I just know the next Mario 3D platformer on Wii U will be better!

I played way too much Skyrim, every day, for about two months, playing all day, it was all I did, I had lots of fun.
As for Super Meat Boy, I was just speed running when ever, visiting the game every little bit.
This year, I also found out about the amazing joy of 4 player NSMB.W, I wish I had a Wii U to play NSMB.U..
Started understanding the secrets of the Pokemon, you know.. EV, IV, breeding and stuff, strated to understand how competitive battling goes, I'll start competitive battling when I get Pokemon B/W2, don't want to get stuck on my borrowed Soul Silver, hehe.
Also, this year, I played my first Metroid game, the original for the NES and Metroid Prime, both really fun games!
And Brawl, I started getting into the game not too long ago, I really want to start playing online.. I think I'll revive the NintendoLife online thread, if you guys have one, hehe.. In case someone might want...

The single favorite of this year, is Metroid, it took the place of my favorite game.

So we can include games from previous years? OK then. I'm going to make a top 6, since I just can't narrow it down to the last 3 in my list.

1. Zero Escape: Vitue's Last Reward - Easily my favorite experience of the year. Absolutely mesmerizing.
2. Xenoblade Chronicles - the best JRPG of this generation.
3. Sakura Wars: So Long My Love - I finally decided to go play this after hearing how it was so great and got horrid sales. Now I wish I got it earlier. It really is an awesome game. It's sad we probably won't see any more of these games.
4. Dead or Alive 5 - Finally, a competitive fighter I actually understand. Easy to grasp gameplay with some seriously deep mechanics. Yeah, it has its flaws, but I never got into fighting games seriously until this one.
5. Halo 4 - To be honest, I was a little dissapointed with this one. Only a little though. The campaign didnt' feel as great as I'd hope. Still, that didn't keep me from loving it, and the multiplayer is quite great... for online, anyways. Getting local multiplayer games set up is a bit of a hassle, since I want to organize it through forge so I can have the experience be like prior Halo games
6. Kid Icarus: Uprising - I was really surprised with this one. I didn't expect to like it as much as I did. Just a really great game that felt unique, not to mention heaps of content.

I haven't had a chance to play some of the best games this year, though. I'm getting Dishonored soon, and I plan on getting Far Cry 3 at some point. Both look really good.

5...Pokemon White 2
4...Kingdon Hearts dream drop distance
3...Colors 3d
2...New super mario bros 2
1...Kid Icarus Uprising: I'm only 14 so I never played the nes or gameboy version. Looking at all the ads I thought I'd give this a try.
Best decision of my life ever.

Out of the games that came out this year, my favorite would be Kid Icarus: Uprising. However, I still don't own a Wii U, and I've yet to buy Paper Mario: Sticker Star. If you want my favorite game of all time, I'd reccomend Zelda Skyward Sword (Wii). Seriously, this is the best Wii game ever, with the Metroid Prime Trilogy coming in second.